Toolbox
HR Zones Calculator
Your five training zones based on maximum heart rate. Reframed as a baseline for tracking progress, not a target to force yourself into.
Your details
Optional — supplying resting HR uses the Karvonen method for more personalized zones. Set to 40 (slider minimum) to use the standard method.
What this means
Your estimated maximum heart rate is 180 bpm using Karvonen method (max HR 180, resting 60 bpm). Your five training zones (in bpm): Zone 1 (recovery) 120.0–132.0, Zone 2 (aerobic base, the key training zone) 132.0–144.0, Zone 3 (tempo) 144.0–156.0, Zone 4 (threshold) 156.0–168.0, Zone 5 (max effort) 168.0–180.0.
What to consider
Zone 2 is where fat oxidation peaks and your aerobic base is built. It should feel like you can hold a conversation but not sing — for most people, this is the zone with the highest return on time invested. Track how your heart rate responds to the same activities over time. As your fitness improves, you will do more work at lower heart rates. That shift is one of the clearest signals of cardiovascular progress.
Medications that may affect your result
Beta-blockers (metoprolol, atenolol, propranolol) significantly lower both maximum heart rate and resting heart rate. If you are on a beta-blocker, your actual zones will be substantially different from these estimates. Heart rate-based zone calculations are unreliable on beta-blocker therapy. Consider using Rate of Perceived Exertion (RPE) instead.
Calcium channel blockers (diltiazem, verapamil) can also lower heart rate, though typically less than beta-blockers.
Stimulant medications (ADHD medications, decongestants) may elevate resting heart rate, which can shift your Karvonen zones.
If you are on heart rate-affecting medications, discuss training zones with your healthcare provider. RPE-based training may be more appropriate.
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About this tool
Formula
Standard method: Max HR = 220 - age. Zones calculated as percentages of max HR. Karvonen method (when resting HR is provided): Target HR = ((Max HR - Resting HR) × intensity%) + Resting HR. The Karvonen method accounts for individual fitness level through resting heart rate.
Zone Definitions
Zone 1 (50-60%): Recovery, warm-up, cool-down. Zone 2 (60-70%): Aerobic base, fat oxidation, conversational pace. Zone 3 (70-80%): Tempo, moderate effort. Zone 4 (80-90%): Threshold, hard effort, limited conversation. Zone 5 (90-100%): Maximum effort, short bursts only.
Known Limitations
220 minus age is a population average with a standard deviation of ±10-20 bpm. Individual max HR varies significantly and decreases with age in a non-linear way. The formula becomes less accurate at older ages. Not appropriate as a hard training target for people on cardiac medications. A proper max HR test with a healthcare provider is the most accurate alternative.
Sources
Fox SM, et al. "Physical activity and the prevention of coronary heart disease." 1971 (220-age formula). Karvonen MJ, et al. "The effects of training on heart rate." 1957.
Educational tool only. Not for diagnostic purposes. Consult a healthcare provider for medical decisions.